On Thu, Jun 12, 2025 at 08:12:59AM -0600, Jeff Law wrote:
> 
> 
> On 6/12/25 4:04 AM, Richard Sandiford wrote:
> 
> > > > Richard, Jeff, it does not seem appropriate to merge this patch now,
> > > > given that it breaks avr and or1k.  Let me know if such experiment is
> > > > desired despite the known breakages.
> > > It's a bit of a judgment call -- we don't require changes to be clean
> > > across every target, that would be an undue testing burden on 
> > > contributors.
> > > 
> > > But knowing it's causing an avr fail means we definitely need to be a
> > > bit more cautious.  An argument could be made that this is a bug in the
> > > avr port -- the code in question looks quite bogus and the fact that the
> > > "fix" is to stop using reload.
> > > 
> > > I think a reasonable step forward would be to put this into my tester
> > > and see if anything else pops out.  If nothing else pops out then I
> > > would suggest we flip the AVR port to LRA and install the patch.  If
> > > other things pop out, then we'll have to revise the plan.
> > > 
> > > So I'll throw it into my tester.  We'll have data on the crosses
> > > tomorrow AM my time.
> > 
> > Thanks, sounds good to me FWIW.  I agree that we shouldn't let dubious
> > port-specific code hold the patch back.  But the cross-port testing
> > would help detect whether there is a legitimate corner case that we
> > haven't thought about.  (Neither the avr nor the or1k cases are
> > legitimate corner cases, IMO.)
> Nothing else popped from that test, either in the runtime builds or new
> testsuite fails.
> 
> So I figured it would be advisable to test LRA on the AVR port.  Many many
> months ago I did a sweep through the reload targets and converted those
> which trivially worked with LRA (ie, everything builds, no testsuite
> regressions).  The fact that AVR still defaults to reload indicates I either
> missed testing AVR or that it failed.  I'm pretty sure it was the latter
> given it just failed :(
> 
> > ./../../..//gcc/libgcc/libgcc2.c: In function '__ucmpdi2':
> > ../../../..//gcc/libgcc/libgcc2.c:2060:1: internal compiler error: in 
> > update_reg_eliminate, at lra-eliminations.cc:1200
> 
> 
> So now the question is do we let this patch go forward now as the two issues
> exposed (or1k, avr) are both target specific issues.  Or do we force this
> patch to wait.
> 
> I'm inclined to wait a week or so to give the port maintainers some time to
> dive into the issues, then go forward.

Pushed as r16-1565-g2dcc6dbd8a00ca.

Thanks,
Dimitar
> 
> Jeff
> 
> 

Reply via email to